Integrated system and method for purifying water, producing pulp and paper, and improving soil quality

ABSTRACT

An integrated system and method for removing excess nutrients from water, for removing the nutrients from the removal site, for enhancing soil, and for producing pulp and paper products includes bioremediating water to be treated with cultured algae or another suitable plant matter in an attached periphyton bed, harvesting the algae/plant matter to produce a wet algal biomass, and mixing the wet biomass with a shredded fibrous material to produce a pulp. The pulp can be molded into a biodegradable package that can be utilized as a delivery vehicle to a site having nutrient-enrichable soil, where the package can be used as a soil amendment after being used as a delivery vehicle. The pulp can also be made into a paper product that is biodegradable and has the characteristic of enhancing soil quality.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part to pending applicationSer. No. 09/211,423, filed Dec. 15, 1998, which is a continuation ofapplication Ser. No. 08/831,736, filed Apr. 1, 1997, now abandoned.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to methods for improving water andsoil and to ecologically beneficial bioremediation, manufacturing, andrecycling methods. The invention further relates, more particularly, toecologically beneficial methods for making pulp and paper products.

[0004] 2. Description of Related Art

[0005] Bioremediation of wastewater from, for example, wetlands ormunicipal effluent has been successfully accomplished with the use ofspecies of plants that remove excess nutrients. Wetland filtration isone such method of bioremediation, but it requires relatively large landareas to accomplish wastewater cleanup. In addition, the nutrients aregenerally left in situ and can under some circumstances be rereleasedinto the environment, such as in a dry-year fire or through succession.

[0006] Other methods use attached algal colonies known as periphyton,which utilize biological pathways to remove and degrade a wide spectrumof pollutants, such as excess phosphorus, nitrogen, carbon, alkalineearth metals, and heavy metals (Adey, U.S. Pat. No. 4,333,263; Jensen,U.S. Pat. Nos. 5,131,820, 5,527,456, 5,573,669, and 5,591,341, thedisclosures of which are incorporated herein by reference). Periphytonfiltration requires far less land area than wetland filtration and alsoretains the nutrients in a confined area from which the algae andingested or sequestered nutrients may be harvested.

[0007] Periphyton filtration has been shown to remove a wide array ofnutrients and other contaminants usually occurring at low levels whencompared with municipal wastewater. The attached algae are known to growat rates exceeding those of terrestrial plants, and a periphytonfiltration system can generate large masses of algae that need to bedisposed of after harvesting, typically by transportation from thebioremediation site to another area for introduction into the soil or tobe used as livestock feed.

[0008] It is known to use the harvested algal biomass as a fertilizer(Snyder and Adey, unpublished, June, 1993) and in pulp production (Sakaiet al., U.S. Pat. No. 5,500,086). It is also known to use pulp fromrecycled paper products to mold packaging and containers (EmeryInternational Developments, Ltd., Toronto, Ontario, Canada, January,1995).

SUMMARY OF THE INVENTION

[0009] It is therefore an object of the present invention to provide anintegrated system and method for utilizing biomass harvested from abioremediation process to produce recycled pulp and paper products.

[0010] It is another object to provide such a system and method toproduce such a biodegradable product that can be further recycled foruse as a soil additive.

[0011] It is a further object to provide such a system and method thatlinks an enhanced biological filtration technique, manufacturingtechnology, and a packaging product to export nutrients from abioremediation site.

[0012] A first embodiment of the method of the present invention is forproducing pulp for use in making a packaging material. The methodcomprises the steps of culturing plant matter in a bed and running waterto be treated thereover. The plant matter should have the attribute ofbeing able to absorb or sequester the material desired to be removedfrom the water. In a specific embodiment the plant matter comprisesalgae in an attached periphyton bed. The plant matter in the bed ispermitted to absorb pollutants/nutrients from the water, which serves tobioremediate the water.

[0013] After the algae has had sufficient time to absorb and/orsequester the material/pollutants that are desired to be removed, andthe bed has grown to a predetermined level, the algae are harvested,which removes the pollutants from the periphyton bed. The harvestedalgae produce a wet algal biomass, which is then mixed with a shreddedpaper product to produce a pulp.

[0014] The pulp can be used, for example, to make packaging, which isbiodegradable in soil and, when added in an approximate range of 10-25%by volume, has been show to improve dramatically the quality of thesoil. In addition, the packaging itself can serve as a vehicle forremoving the excess nutrients from the bioremediation site or basin,thereby increasing the ecological efficacy and benefits of the method.

[0015] In a second embodiment, another bioremediation plant, acombination of more than one of such plants, or a combination of one ormore of such plants with algae is used as the biomass.

[0016] In a third embodiment, the first embodiment of the method andsystem as described above is extended to make a paper product from thepulp produced thereby.

[0017] The features that characterize the invention, both as toorganization and method of operation, together with further objects andadvantages thereof, will be better understood from the followingdescription used in conjunction with the accompanying drawing. It is tobe expressly understood that the drawing is for the purpose ofillustration and description and is not intended as a definition of thelimits of the invention. These and other objects attained, andadvantages offered, by the present invention will become more fillyapparent as the description that now follows is read in conjunction withthe accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

[0018] The FIGURE schematically illustrates a system for producing pulpfrom harvested biomass.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A description of the preferred embodiments of the presentinvention will now be presented with reference to the FIGURE.

[0020] A first embodiment of the invention comprises a method forproducing pulp for use in making a packaging material. This methodcomprises the steps of culturing a desired plant matter in a bed andrunning water to be treated over the bed. As above, the plant mattershould be able to absorb or otherwise sequester the material to beremoved from the water. In a specific embodiment the plant mattercomprises algae, and the bed comprises an attached periphyton bed. Thewater may be run continuously or retained for a specified time upon thebed, depending upon the level of remediation required/desired. While thewater is in contact with the algae, pollutants and/or excess nutrientsare absorbed which bioremediates the water.

[0021] In a particular embodiment, water within a basin 13, the edge 11of which defines a watershed of the basin 13, is fed by gravity flowinto a lake 12. This water to be treated 21 can then be pumped via pump24 through water line 15 to the inlet 22 of the bed 20.

[0022] When desired, the algae are harvested, which removes thepollutants/nutrients from the periphyton bed. The harvest comprises awet algal biomass, which can be partially dried to thicken it, and whichcan then be mixed with a shredded paper product such as to shreddedrecycled newsprint produce a pulp.

[0023] It should be appreciated by one skilled in the art that, eitherin addition to or instead of algal periphyton, other bioremediationplant(s) can be employed, including, but not limited to, water hyacinth(Eichhornia crassipes), dollar weed, water lettuce, and duckweed.Therefore, the term algae is not intended as a limitation on the presentinvention.

[0024] The system 10 for producing pulp 50 is illustrated in the FIGUREand comprises a plant matter support bed 20, such as an attachedperiphyton bed, for culturing plant matter 30 such as algae or anotherwaste bioabsorber and an inlet 22 for admitting water to be treated 21into the bed 20. A harvester 23 is adapted to remove the plant matter 30and the absorbed pollutants/nutrients from the bed 20. The wet biomass25 formed thereby is then dewatered in any device as is known in the art29 and blended in a mixing vat 26 with a shredded paper or fibrousproduct 27 to produce a pulp 50.

[0025] A second embodiment of the invention comprises a method forproducing a biodegradable package 32. This method comprises the steps asabove in the first embodiment, with the addition that the pulp is moldedinto a package 32 that is biodegradable in soil and may be used tofertilize soil.

[0026] The system for producing a biodegradable package, . . . so shownin the FIGURE additionally comprises a mold 31 for molding the pulp 50into a package 32.

[0027] A third embodiment of the present invention comprises anintegrated method for removing excess nutrients from wastewater 21 andfor removing the nutrients from the removal site. This method comprisesthe additional step of utilizing the package 32 as a delivery vehicle toa site 33 having nutrient-enrichable soil 34, where the package can beused as a soil amendment after being used as a delivery vehicle. Thesoil quality is improved by providing the absorbed nutrients, aidingwater-retention capability, and increasing soil binding or tilth toreduce erosion and promote aeration.

[0028] A possible highly integrated embodiment of this method wouldentail locating a package-manufacturing facility in close proximity tothe periphyton filtration system. The molded packages 32 could be usedas delivery boxes for sending other articles to a second site 33 knownto be in need of soil amendment. Such boxes could include, but are notintended to be limited to, pots for horticultural products, which couldbe planted into the soil directly without being removed from thedelivery box, egg cartons, packaging filler sheets, loose fill(“peanuts”), packaging shock protection and positioning elements, and“cardboard” mailing boxes. This method has the added advantage ofeliminating the need to dispose of the packaging in a landfill or byburning.

[0029] It may be appreciated by one skilled in the art that additionalembodiments may be contemplated, including the use of other types ofplant matter and fibrous material to manufacture the pulp.

[0030] In the foregoing description, certain terms have been used forbrevity, clarity, and understanding, but no unnecessary limitations areto be implied therefrom beyond the requirements of the prior art,because such words are used for description purposes herein and areintended to be broadly construed. Moreover, the embodiments of theapparatus illustrated and described herein are by way of example, andthe scope of the invention is not limited to the exact details ofconstruction.

[0031] Having now described the invention, the construction, theoperation and use of preferred embodiment thereof, and the advantageousnew and useful results obtained thereby, the new and usefulconstructions, and reasonable mechanical equivalents thereof obvious tothose skilled in the art, are set forth in the appended claims.

What is claimed is:
 1. A method for producing a paper product, themethod comprising the steps of: culturing algae in an attachedperiphyton bed; running water to be treated over the periphyton bed;permitting the algae to sequester a pollutant from the water, therebycleansing the water; harvesting the algae, thereby removing thepollutant from the periphyton bed, to produce a wet algal biomass;mixing the wet algal biomass with a shredded fibrous material to producea pulp; and producing a paper product from the pulp.
 2. The methodrecited in claim 1, further comprising the step, following theharvesting step, of partially dewatering the algal biomass to thickenthe algal biomass.
 3. The method recited in claim 2, wherein theshredded fibrous material comprises shredded recycled newsprint.
 4. Asystem for producing a paper product, the system comprising; an attachedperiphyton bed for culturing algae; means for admitting water into theperiphyton bed, wherein the algae absorbs pollutants from the water, andthereby bioremediates the water; means for harvesting the algae, therebyremoving the pollutants from the periphyton bed, the harvested algaeforming a wet algal biomass; means for mixing the wet algal biomass witha shredded fibrous material for producing a pulp; and means forproducing a paper product from the pulp.
 5. The system recited in claim4, further comprising means for partially dewatering the algal biomass,for thickening the algal biomass prior to mixing with the shreddedfibrous material.
 6. A method for producing a biodegradable paperproduct comprising the steps of: culturing algae in an attachedperiphyton bed; running water to be treated over the periphyton bed;permitting the algae to absorb pollutants from the water, therebybioremediating the wastewater; harvesting the algae, thereby removingthe pollutants from the periphyton bed, to produce a wet algal biomass;mixing the wet algal biomass with a shredded fibrous material to producea pulp; and producing from the pulp a paper product that isbiodegradable in soil and fertilizes the soil.
 7. The method recited inclaim 6, further comprising the step, following the harvesting step, ofpartially drying the algal biomass to thicken the algal biomass.
 8. Asystem for producing a biodegradable paper product, the systemcomprising: an attached periphyton bed for culturing algae; means foradmitting water to be treated into the periphyton bed, wherein the algaeabsorbs pollutants from the water, and thereby bioremediates the water;means for harvesting the algae, thereby removing the pollutants from theperiphyton bed, the harvested algae forming a wet algal biomass; meansfor mixing the wet algal biomass with a shredded fibrous material, forproducing a pulp; and means for producing a paper product from the pulp,the paper product biodegradable in soil and adapted to fertilize thesoil.
 9. The system recited in claim 8, further comprising means forpartially drying the algal biomass, for thickening the algal biomassprior to mixing with the shredded fibrous material.
 10. A method aproducing a paper product, the method comprising the steps of: culturinga plant material in a confined bed, the plant material capable ofabsorbing or sequestering a pollutant from water; running water to betreated over the bed; permitting the plant material to sequester apollutant from the water, thereby cleansing the water; harvesting theplant material, thereby removing the pollutant from the bed, to producea wet biomass; mixing the wet biomass with a shredded fibrous materialto produce a pulp; and producing a paper product from the pulp.
 11. Themethod recited in claim 10 further comprising the step, following theharvesting step, of partially dewatering the biomass to thicken thealgal biomass.
 12. The method recited in claim 11, wherein the shreddedfibrous material comprises shredded recycled newsprint.
 13. The methodrecited in claim 10, wherein the plant material is chosen from a groupconsisting of water hyacinth, dollar weed, water lettuce, and duckweed.14. A system for producing a paper product, the system comprising: a bedfor culturing plant material capable of absorbing or sequestering apollutant from water; means for admitting water into the bed, whereinthe plant material absorbs a pollutant from the water, and therebybioremediates the water; means for harvesting the plant material,thereby removing the pollutant from the bed, the harvested plantmaterial forming a web biomass; means for mixing the wet biomass with ashredded fibrous material for producing a pulp; and means for producinga paper product from the pulp.
 15. The system recited in claim 14,further comprising means for partially dewatering the biomass, forthickening the biomass prior to mixing with the shredded fibrousmaterial.